The Hardest Case
by OhHappyDay2000
Summary: The girls are at impasse. With A's threats getting more dangerous than ever before and with their reluctance to tell anyone about their nightmare it seems that all is lost. Will the BAU be able to finally solve the mystery and return peace to Rosewood?
1. A New Case

_**Hi Everyone, **_

_**This is a little author's note before the beginning of my story. I don't mean to step on anyone's toes but someone else has already begun writing a story like this. I used their idea but it will be completely different and I will most certainly update regularly. I've been waiting for a cross-over between criminal minds and pretty little liars for ages and since the other story is not being updated fast enough I thought I would add my own. All characters belong to Pretty Little Liars and Criminal Minds. To the authors of the other cross-over story – please tell me if you want me to take this down! I've just been waiting for so long and can't wait any longer! **_

_**I hope everyone enjoys reading this as much as I am enjoying writing it! **_

_**~OhHappyDay2000**_

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><p><em><strong>Chapter 1 – A New Case<strong>_

It was obvious the team was exhausted as soon as they stepped into the BAU headquarters in Quantico, Virginia and after their most recent case it was not surprising.

They had just returned home after a particularly nasty unsub had raped and brutally butchered seven young adolescents. The BAU fortunately caught him before the eighth but the loss of such a young life that they had just witness had left them completely without energy. That was often the case and yet again they murmured their saddened goodbyes for although they had caught yet another killer they all knew another would take his place. What they didn't yet know was that it would happen very soon.

It was three o' clock in the morning when Special Agent Aaron Hotchner finally climbed into bed after a long, agonising night. One of the things he regretted about his job was the paperwork! If anything, it was the part he hated the most especially as he had to re-live each case in order to file it and close it for good.

It seemed as if he had just shut his eyes when the phone rang obscenely loudly and he was startled awake. Hunting for the receiver he finally grasped it in his hand, a few seconds passed before a sure 'We'll be there' rang in the empty room.

Hurriedly slipping on a suit he hastily dialled the team and less than two hours later they were on the jet, flying to the little town of Rosewood, Pennsylvania.

'There have been a number of cases in this area that have slipped our radar recently, all of them revolving around bizarre incidents leaning towards murder' Hotch began presenting the case.

'The disappearance of adolescent girl Allison last year triggered a whole range of events that cause community to recoil into itself. Up to date, a whole number of other incidents such as disappearances, shoplifting and reported murders began occurring in the town, all revolving around four of the girl's friends'.

'Umm, sorry Hotch but what has this got to do with us? I mean, there weren't actual murders were there?' meekly interrupted Reid, not wanting to disturb the boss.

'It says here that there was one particular incident in which there was a reported murder but the body was never found.' Morgan read out loud, 'Yeah, sorry Hotch but what's this got to do with us?'

'Guys look at the time line, Allison disappeared a year ago and now the main suspect, one Ian Thomas has just turned up dead. Hotch is right, this is definitively dodgy' said Emily.

'The four girls are called Aria Montogomery, Hannah Marin, Emily Fields and Spencer Hastings. So far, the police haven't been able to get anything out of them. They're hiding something and according to the PD over there, more people might be at risk. It's our job to try and understand what is happening and capture whoever might be responsible if there is someone responsible. We can't leave anything to chance'. stated JJ.

'Hotch and I thought it might be easier to understand the girl's behaviour if we placed some of you with them.' added Rossi.

'Reid you'll be with Spencer – you're both high achievers. Try to get a common ground, she might find it more comfortable to be around someone as academically oriented as her. It might push her to reveal something!' JJ handed over a manila folder, in it, information detailing Spencer's life.

'Prentiss, you're with Hannah. Hannah is a wild child. She's had a few brush ups with the law, nothing major, a few thieving incidents. Her family initially thought this was caused by her father leaving earlier this year but now they're not so sure. She's apparently getting more secretive.'

'Morgan, you get Aria. She's apparently very into English and had somewhat of a rocky past with her family too. Her father cheated on her mother and asked Aria to lie for her. She too has recently begun avoiding her family. Try and find out if this is because of the incident with her father or because of some other issue.'

'Finally, Rossi' began JJ 'I'll go with Emily. Star athlete, swimmer she recently was hospitalized for a stomach ulcer. We all know what that suggests. I'll try and figure out what possibly motivated her to take steroids' finished Rossi.

'Remember this is strictly confidential' said Hotch. 'Anything you find out gets reported to the team first, then to the parents. If we compromise the girl's trust then we will have lost our best point of access into this investigation. Also, the police in this town is very, rustic. They don't trust outsiders and they just want to close the case, they're not looking for the truth. We are. 'Everyone, start reading up on who you'll be spending time with...'

'I've arranged with the families that we can stay with them so that we can more closely monitor their activities!' mentioned JJ.

'Perfect.' Continued Hotch. 'We need to get to the bottom of this, fast, before anyone else gets hurt. We'll be landing in a few hours'.


	2. The Girls

**_Thank-you so much for all the hits I've received on this story! I hope you'll enjoy this chapter! Please feel free to send me suggestions :)_**

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><p><em><strong>Chapter 2 – The Girls<strong>_

English, Spencer, Emily and Hannah thought was one of the best classes in their curriculum if only because they got to watch Aria making googly eyes at Mr Fitz, him, responding in turn when he thought no-one was watching.

He made one of those faces right now staring right at her. The trio were confused as to how on earth the relationship escaped them. If one paid attention, the close rapport between Aria and Mr Fitz was blatantly obvious!

Hannah exasperatedly shook her head, seeing Aria beginning to erotically suck on a pencil, constantly maintaining eye contact with the now flustered teacher. Spencer, however, just frowned – if those two weren't more careful what they had was not going to end as well as was hoped!

Aria was still in the middle of enjoying the reaction she provoked from Ezra. His face was red and he kept on making erratic, twitchy hand movements as if he couldn't sit still. A pity that he was trying to look every-where but her, she missed seeing him outside of school but with mid-terms coming up and the terror A constantly provided, her life was too busy to stage a secret encounter!

The ringing sound of the bell snapped her out of her reverie, Mr Fitz's voice marking the end of class.

'Alright everyone, I want a character analysis on Helena from 'A Midsummer's Night Dream' on my desk by next week!'

The thud of closing books and rustle of papers rang out, followed by a flurry of students trying to get out as soon as possible.

'I'll catch up with you later' said Aria leaving Hannah, Emily and Spencer to smirk

'Ok, see you' murmured Emily. Perpetually the quiet one of the group!

Ezra looked up just as Aria closed the door and shut the blinds.

'Hey, riveting class today Mr Fitz!' she said.

Ezra gave her an amused glance 'Why thank you Aria, although you paid more attention to how to best fluster me instead of on a certain Shakespeare play we're studying!'

'I miss you' she stated.

'I know, I miss you too but you can't keep doing that in class Aria! I need this job and I would really like to stay out of jail! I love you. We both knew this wasn't going to be easy when we entered into it but we need to stay focused for a few more years. It's won't be long until we'll be able to hold hands and have coffee in public'

'I'm sorry. I didn't mean to. I just – I want time to hurry up!'

'Me too, come to my place on Saturday? We can order take-out, maybe watch a movie?'

'Yeah, sure thing, see you Mr Fitz.' She smiled.

They both started to lean in for a stolen kiss but halted. They were still at school.

'Bye' said Aria with a sad grimace.

'Yeah, bye,' whispered Ezra as he watched her walk out the door. This was most certainly messed up, he thought.

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><p>Aria had just reached the table where the others were sitting when an announcement startled them out of conversation. 'Spencer Hastings, Hannah Marin, Emily Fields and Aria Montgomery please report to the principal's office'.<p>

The four looked at each-other before slowly getting up. The whispers had already started by the time they were on their feet, the stares burning holes in their backs.

'What could this be about?' questioned Emily 'Do you think they found out about… ' the question was left open. No-one wanted to even contemplate what A would do to them if any-one found out about her. As if right on cue, their phones buzzed. Hesitantly they all reached into their bags, a new threatening message displayed on the tiny screens:

"_Wow, the principal's office. Are you scared? You should be. Don't worry, no one's found out about me yet but they'll find out all about you very soon! All your secrets out into the open! This has just turned into a party! _

_A"_

'What on earth does the bitch mean?' said Hannah.

'I guess we'll find out soon enough' dryly replied Spencer as they entered the office crammed with people.


	3. Who gets Who

_**Hi Everyone, **_

_**I am so, so, sorry for the long update! I went on a holiday and didn't take my laptop with me! I truly, sincerely apologize! I realize I'm kind of a hypocrite now… I posted this story just so readers could get more regular updates and here I am, I've let you all down! I'm truly sorry! So far, everyone has been so wonderful! Thank-you so much for the reviews, favourites and story alerts! You're all wonderfully brilliant! Sorry again about the slow update! I promise they'll be faster coming! Enjoy and let me know of any errors or mistakes etc. It would be greatly appreciated! **_

_**Love, **_

_**~OhHappyDay2000**_

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><p><em><strong>Chapter 3 – Who gets Who<strong>_

The principal's office was filled with people, most, completely unknown to the girls. In fact, the only people they did know were Detective Wilden, Officer Reynolds and their principal. The rest was comprised of a middle aged man, a short brunette, a pretty blond woman, a tall handsome man, a stick-thin boy in his 20s and a seemingly perpetually serious, suited up… lawyer would be the best word to describe him!

It felt quite warm and stuffy in the tiny office and the four began to feel quite uncomfortable.

They'd often been interviewed by police following the disappearance of Ally but the suited men and women tacitly standing in front of them led the girls to believe that this was a whole lot more serious.

The blonde, pretty one beckoned them to sit down on a tiny couch. Once they were appropriately squished the principal began talking.

He was a pudgy, short man. Pointing to each one of them in turn he introduced them to the team. 'These are Aria, Hannah, Spencer and Emily. Girls… considering the most recent, uhhh, events local police thought it be best to bring in ehh, the big guns, umm, the ….'

Detective Wilden impatiently interrupted 'We decided to bring in the FBI, maybe they'll be able to find out what exactly you all are hiding!'

Spencer noticed the tall, tanned one slightly glare at the detective. He looked to the blonde one and she nodded imperceptibly. What was that all about, she wondered silently.

It was at that point that the FBI really took charge. The blond one stepped forward, 'Good Morning to all of you, my name is JJ and I'm the public liaison for the BAU. We're specialized in noticing behaviour; profilers would be the word you'd use. We're here to try to help solve the mystery of Allison. We're not here to lock you away; we're simply here because we want to figure out what happened. We want to know the truth.'

It was obvious, by that statement alone, that the FBI weren't exactly fond of how the case had been handled by the Rosewood PD. That rivalry, well, that should be interesting thought Spencer!

The 'lawyer then', began talking 'I'm Special Agent Aaron Hotchner this is SSA Morgan, he pointed to tall, tanned, this is SSA Prentiss, the brunette gave a slight wave, Dr Reid, the boy just shyly looked down, you already know JJ and this is SSA Rossi, the older one simply nodded.

Even considering the situation Hannah couldn't help casting an appreciative look towards Morgan. It wasn't often she saw such gorgeousness in school. Excluding Caleb and Mr Fitz of-course!

'For the next couple of days or so, you'll be allocated an agent,' continued JJ, 'that agent will be acting as though on protective duty so you'll be protected at all times. You will travel with them to and from school. The will attend classes with you and reside with you. We've already talked to your parents in regards to this. We will try not to suffocate you but it's important that your lives are safe, at least until we catch the culprit.'

Aria shot Emily a panicked look. The latter understood – with the FBI around 24/7 Aria and Mr Fitz would be in severe danger of getting caught! Whilst Emily knew Mr Fitz wouldn't do anything to hurt Aria, it sure wouldn't look that way to the feds!

Rossi, who was scanning the girls' faces, noticed the sudden panic. Yes, these girls definitively had something to hide.

'Aria you're with Morgan. Hannah you'll be with Prentiss, Emily you're with Rossi and Spencer you're with our infamous Dr Reid.' announced Hotchner. These agents will accompany you girls home tonight and you can take some time to get to know each-other! We're sorry about the intrusion, we are, but if we are to catch whoever murdered your friend this is a necessary step!

The principal nodded 'Ok, girls you may now go back to class' he said ushering them out the door. There was no doubt he was thrilled that the whole encounter was over!

Emily could bet, he was scared of law enforcement… something in his past, or maybe just plain cowardice!

The girls looked at the agents that were to reside with them. There was nothing about this arrangement that pleased them. Up to know, they'd had the freedom of being able to quietly investigate Allison's death. With the FBI constantly watching their every move, snaking out was going to be impossible! The girls shuddered at what A would make them do if they couldn't meet her demands! No, this truly was not good! Heads down, they walked back to class


	4. Realizations

**__Hey Everyone, **

**Happy New Year! I'm again, really sorry about the long time between updates. My grandfather hasn't been well and so I haven't had much time to really concentrate on this story in a while! I wasn't sure where I wanted it to go! I fortunately got an epiphany a few days ago so I been planning and writing trying to make it come together in my head before putting it on paper! Again, I'm really sorry! Hopefully, updates will be hurrying up in the future! Thank-you so much for all the reviews, favourites and alert! They really mean the world to me!**

**Love, **

**OhHappyDay2000 3**

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><p><em><strong>Chapter 4 – Realizations<strong>_

As soon as the four had left the BAU asked to be left alone. It was only then that they began truly discussing the case.

'Did you notice their reactions when we said we were going to be protecting them?' asked Rossi.

'They all looked ecstatic' responded Emily with her usual, heavy dose of sarcasm.

'Spencer seemed to be the most observant of the four' commented Morgan. 'She definitively saw my dislike for Detective Walden when he was talking to them!'

'That guy needs to be kept in check' said JJ 'He's already convinced that they're guilty!'

'Aria looked so tense she was about to break when we said we'd stay with them for a few weeks! She looked the most afraid.' said Reid, 'She was really scared of the idea of us finding something out.'

'Morgan, get Garcia to look up their background etc. maybe they visit social networking sites that can give us more information' said Hotch. 'Until then, we stay with each of the girls as planned'

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><p>'Shit! Shit! Shit! Shitty, shit! Shit!' Hannah kept on repeating the profanity and it was driving the rest of them insane!<p>

'Hannah, just shut up! I think we all agree on the direness of the situation!' said Emily, followed by a nod of agreement from the others.

They were all in the school's library very well pretending to be studying! It really was just an excuse to formulate some sort of plan.

According to the text they received moments before the meeting with the FBI, A already knew about the arrangement and A seemed to like the whole 'shadowed by the FBI thing'. That alone was cause for alarm, everything A liked was usually tied to their sufferance.

'Alright, alright, let's just think about this for a second!' said Spencer 'We have each been assigned a 'protection' agent who will stay with us for the next couple of weeks. Said agent will observe our behaviour and attempt to investigate into Ali's disappearance and subsequent murder. Said agent will thus make it impossible for us, when around, to discuss everything regarding A.'

'Alright Spence, enough with the analysis' commented Hannah. 'No A talk around the goons!'

'They aren't goons! They're FBI Agents!' protested Spencer

'Whatever they are, we get it Spence! No talking about anything even remotely about A or Ali around them! We got it when A got rid of Dr Sullivan and made everyone else who we told about the creepy bitch, suffer!'

Emily sighed and then emitted a giggle 'When did everything get so complicated?' she asked the empty air.

Hannah smiled and then let out a full blown laugh, Spencer joined in soon after and the three girl's peals of desperate laughter rang out in the silent library.

It took them a few minutes to realize that they weren't all laughing at their situation.

'Aria?' said Emily looking to her friend. 'You haven't said anything since we got back, is everything ok?'

Aria was sitting on a chair, crossed legged, staring into space. In that very moment she was truly afraid. She loved Ezra, she loved him more than she'd ever loved anyone. Their relationship, though beautiful and right in their eyes was nothing but ugly and wrong in the eyes of society. If one of the agents found out about their relationship, Ezra's life would be ruined. He would be put to trial and open to public humiliation, the loss of his teaching licence. Most likely, his freedom as well, he would be locked up, all for something she initially pursued. She gritted her teeth, it was all her fault.

'Earth to Aria' said Hannah, waving her arms in front of Aria's face.

Aria suddenly stood up and hastily scrambled to put away her things.

'Where are you going?' asked Spencer worriedly.

'I need to go tell him.' She said before tearing out of the library.

The three remaining girls looked at each-other knowingly. Aria and Mr Fitz had to be more than careful now. They had to be paranoid and even call a hiatus. The danger meter of someone finding out about their relationship was now in the 'extreme' section.

'So, is anyone up to some real studying?' Joked Hannah, half-heartedly

There was no surprise when nobody laughed.

'


End file.
